Detection of extended-spectrum ß-lactamase in Enterobacter spp.--evaluation of six phenotypic tests.

Extended-spectrum ß-lactamases (ESBL) are plasmid-mediated enzymes that hydrolyze cephalosporins and monobactams. The lack of a standard method to detect ESBL in Enterobacter spp. has led to underestimating its frequency. The aim of this study was to evaluate ESBL detection in Enterobacter spp. By the double-disk synergy test (DDST) and combined disk test (CDT) assay using cefepime, cefotaxime, and ceftazime as substrates for ESBL, plus AmpC inhibitors in different associations. A total of 83 Enterobacter spp. ESBL and 31 non-ESBL Enterobacter spp. were tested, and a cutoff point ≥3 mm was defined using a receiver operating characteristic (ROC) curve for combined disc methods. All tests showed 100% specificity. The sensitivity was 89.2% for DDST and CDT without AmpC inibitor, 90.4% in the combined disc test in Mueller-Hinton agar containing phenylboronic acid (CDT-PBAA), and 94% in the combined disc test in Mueller-Hinton agar containing cloxacillin (CDT-CLXA). Cefepime was the best substrate, mainly when AmpC inhibitors were not used. However, superior results were achieved when all cephalosporins were evaluated together. In conclusion, to improve ESBL detection in Enterobacter spp., some modifications in phenotypic tests are needed, such as to reduce the distance between the discs to 20 mm in DDST, to use a cutoff point for ≥3 mm on the CDT, and to include a cefepime disk or an inhibitor of AmpC in all tests.

Cefepime versus extended spectrum ß-lactamase-producing Enterobacteriaceae.

The objective of this study was to evaluate the susceptibility to cefepime of a large group of ESBL- producing enterobacteria recently isolated in a Brazilian teaching hospital . The study included 280 strains of ESBL-producing enterobacteria, isolated between 2005 and 2008. The presence of the genes blaCTX-M, blaTEM and blaSHV was determined by PCR and confirmed by nucleotide sequencing. Susceptibility testing for cefepime was performed by disc-diffusion, agar dilution method and E-test®. Among the isolates, 34 (12.1%) presented a cefepime inhibition zone > 21 and MIC < 8 mg/L by agar dilution and E-strip methods. The use of cefepime for the treatment of infections caused by ESBL-producing bacteria has been controversial. Some studies of PD/PK show the probability of achieving the required PD parameters for cefepime, when the MICs were < 8 mg/L, whereas others have reported therapeutic failure with the same MIC. Additional data is essential to come to terms about the report and treatment with cefepime in ESBL-producing organisms especially when these microorganisms are isolated from sterile sites and from critically ill patients.

Cefepime versus extended spectrum β-lactamase-producing Enterobacteriaceae

The objective of this study was to evaluate the susceptibility to cefepime of a large group of ESBL- producing enterobacteria recently isolated in a Brazilian teaching hospital . The study included 280 strains of ESBL-producing enterobacteria, isolated between 2005 and 2008. The presence of the genes blaCTX-M, blaTEM and blaSHV was determined by PCR and confirmed by nucleotide sequencing. Susceptibility testing for cefepime was performed by disc-diffusion, agar dilution method and E-test®. Among the isolates, 34 (12.1 percent) presented a cefepime inhibition zone > 21 and MIC < 8 mg/L by agar dilution and E-strip methods. The use of cefepime for the treatment of infections caused by ESBL-producing bacteria has been controversial. Some studies of PD/PK show the probability of achieving the required PD parameters for cefepime, when the MICs were < 8 mg/L, whereas others have reported therapeutic failure with the same MIC. Additional data is essential to come to terms about the report and treatment with cefepime in ESBL-producing organisms especially when these microorganisms are isolated from sterile sites and from critically ill patients.

High prevalence of rheumatoid factor associated with clinical manifestations of rheumatic disease in Kaingang and Guarani Indians from Southern Brazil.

The aim of the present study was to perform a screening for rheumatoid factor (RF) and anti-nuclear antibody in Kaingang, Guarani and Mestizos individuals from Mangueirinha Reservation, State of Paraná, Brazil, and associate it with demographic and clinical data. Serum samples from 321 aborigines (125 male and 196 female; 4-86 years old) and 180 non-Indians healthy individuals were analysed (62 male and 118 female; 2-81 years old). Antinuclear antibody (ANA) was tested by indirect immunofluorescence, and RF by agglutination in latex and turbidimetry. RF was higher in Kaingang when compared to Guarani (P = 0.009), Mestizos (P = 0.061) and non-Indians (P = 0.010). A significant increase of RF was observed in Kaingang women versus Kaingang men (P = 0.002) and, among the women, in Kaingang when compared to Mestizos and Guarani (P

O sistema complemento nas doenças: genética e patogenia / The complemente system in diseases: genetic and pathogeny

O sistema complemento é parte fundamental da imunidade inata e contribui na remoção de complexos imunes e na ativação de processos inflamatórios. Essas proteínas representam um meio rápido e eficiente de proteção do hospedeiro contra microorganismos invasores. Associações entre complemento e doenças são observadas em situações de deficiência do complemento, anormalidades na regulação do complemento e nas inflamações. Ativação imprópria ou excessiva do complemento pode levar a conseqüências lesivas em virtude da grave destruição tecidual inflamatória. Evidências clínicas e experimentais ressaltam o papel do complemento na patogênese de inúmeras doenças inflamatórias, que incluem não apenas doenças por imune-complexos e auto-imunes, como também falência de órgãos subseqüentes a sepse, traumas múltiplos e queimaduras. O polimorfismo genético tem sido descrito para diversos componentes de membrana, proteínas solúveis de controle e receptores do sistema complemento. Atualmente, o polimorfismo dos componentes do complemento pode ser estudado usualmente, tanto pela pesquisa fenotípica das variantes protéicas (fenotipagem) como pela caracterização genômica do DNA (genotipagem), e tem contribuído para o entendimento da patogênese de diferentes enfermidades. Doenças imunologicamente mediadas estão associadas às variantes alotípicas do complemento, em particular lúpus eritematoso sistêmico, artrite reumatóide, esclerose múltipla, doença celíaca, deficiência de IgA e IgG4, entre outras. A presente revisão tem por objetivo dar uma visão dos conhecimentos atuais na área da genética do complemento, bem como da participação desse sistema na patogenia de diferentes doenças.

Conceitos atuais na ativação do sistema complemento e suas propriedades biológica / Recent concepts in the activation of complement system and biological properties

O sistema complemento é formado por aproximadamente 35 proteínas e glicoproteínas distribuídas no plasma, outros líquidos biológicos e superfícies celulares. Essas proteínas atuam em uma reação sequencial em cascata e representam um dos principais mediadores da defesa inata do hospedeiro e da inflamação. A ativação do sistema complemento tanto pode ser benéfica para o hospedeiro, como na resistência a microrganismos invasores, como pode ser deletéria em uma variedade de doenças imunopatologicamente mediadas. O complemento pode ser ativado por qualquer das três vias, a via clássica, dependente do anticorpo, a via alternativa ou a recém-descrita, via das lectinas (MBL). As consequências biológicas da ativação do complemento são principalmente a defesa contra infecções piogênicas, a interação entre imunidade inata e adaptativa e a remoção de complexos-imunes e produtos da injúria tecidual. O complemento reconhece, opsoniza ou lisa partículas, incluindo bactérias, leveduras e outros microrganismo, restos celulares e células alteradas do hospedeiro. Há também evidências de que o complemento contribui significativamente na regulação da resposta imune. O principal objetivo da presente é revisão é fornecer uma visão atual da ativação e das propriedades biológicas desse sistema, enfatizando sua importãncia na resposta imune inata e na homeostasia do hospedeiro.